摘要:Ship hull and propeller fouling has a severe impact both on fuel costs and on greenhouse gas emission, thus, it is an important subject to consider when developing a maintenance plan to enhance energy efficiency and reduce gas emissions from ships. This paper presents a two-step approach for evaluating the actual propulsive performance of a ship through analyzing continuous onboard measurement. First, the onboard monitored data are corrected for the wind and wave effects using fast and transparent empirical methods. Second, the corrected data are filtered based on hydrodynamic criteria. A case study is presented to demonstrate the effectiveness of the methodology. Subsequently, the processed data are analyzed by mathematical tools to derive an engine power–rpm curve to represent the actual propulsive performance of the ship. By comparing the derived curve against the nominal curve for engine design, it is possible to identify the deterioration of the ship’s condition, which is the key task in developing the identification capability that is needed in a proactive maintenance procedure. This methodology is expected to support the maritime sector in combating climate change by reducing the Greenhouse Gas (GHG) emissions from ship operations.